Thre really isn't much vhoice with pony weapons, they sinply do not have the versatility that having hands presents us. And yeah all their options are fairly inpracticle, bu keep in mid the other side they are fighting has the exact same limitations, and more, the Zebras didn't have unicorns that could TK.
And yes they address the recoil, most pony guns seem to be designed to have minimal recoil, and the more powerful ones are outright stated to only be useable by the strongest EP's or unicorns via TK. And the bigger guns are basicly side mounted guns and while they would be hard to aim and be good with, with enough practice that can be overcome, Calamity is an expert marksman who uses Battle Saddle weaponry.
And far as i'm concerned every fic takes place in it's own AU. Yes FOE can get Dark, but it's never Grimdark, the darkness is there as a tool, not for the sake of being dark, in the end it is about hope, how no matter o=how bad it seems, sometimes all it takes is the right little spark to set the blaze that will burn away the darkness and bring back the light of hope.
As to the canon ponies fates, over all, yes some of them do get pretty bad, but really it's not many that dont end up getting either a decent ending, or at least make it worth it.
Twilight-spends the time since the war as part of the Goddess Gestalt, but survives long enough afterwards to save lil'pip and hear Pinkie Pie's last message to her, telling her she was right and that Pinkie was going to work at becoming the old Pinkie. RD-ultimate fate unkown, though last seen trapped in SPP command, with Gilda flying around outside to kill her if she comes out. Fluttershy-Trapped as a tree by Killer Joke, but eventaully cured and helps to rebuild Equestria. Rarity-Sacrifices herself to save Fluttershy, Pinkie-Realizes how she's bucked up her life, admits she needs to change and begins to work on fixing it, only for the bombs to fall (probably the most tragic of the mane 6's ends) AJ-Lives a long full life in Stable 2, eventually dying of old age.
Build a fool proof system, and the world will create a better fool.
My random thoughts